Controlling wireless device registration based on vehicle movement

ABSTRACT

A wireless communication device integrated with a vehicle operates in a reduced-registration mode while the vehicle ignition is off. In the reduced-registration mode, the wireless communication device periodically determines, based at least on vehicle control system data such as odometer data or wheel-rotation data, whether the vehicle has moved at least a threshold extent, and if so the wireless communication device engages in air interface registration. The arrangement helps to conserve vehicle battery power while the ignition is off, while keeping a serving radio access network apprised when the vehicle has been moved sufficiently, so that the network can more readily route messages such as telematics commands to the vehicle.

BACKGROUND

In normal practice, when a cellular wireless communication device is inan idle state, the device may periodically engage in air interfaceregistration with a serving radio access network. This periodicregistration helps the network keep track of where the wireless deviceis located (e.g., in which cell sector of the network), so that thenetwork can appropriately route page messages, text messages, controlmessages and the like to the wireless device.

OVERVIEW

One problem with this periodic registration function is that it tends toconsume limited battery power. Consequently, if a device is running onbattery power and is left in the idle state for a sufficiently longperiod of time, its periodic registration may be a significant factor inthe device ultimately running out of battery power.

While such loss of battery power may be inconvenient for a user of aportable wireless communication device (such as a handheld cell phone orwirelessly-equipped computer for instance), the user can easily resolvethe problem by simply connecting the wireless device to a charging portto charge the battery.

A more significant problem can arise, however, in a scenario where thewireless communication device is integrated with a vehicle, such as tofacilitate wireless communications to and from the vehicle. A practicalexample of such an arrangement is where a wireless communication deviceis integrated with a vehicle control system to facilitate telematicsfunctions such as wirelessly receiving and responding to commands unlockthe vehicle doors (e.g., where a user has locked his or her keys in thevehicle), to cut off the vehicle's ignition (e.g., where the car isreported stolen and should be disabled), or to report the vehicle'slocation. Further, such an integrated wireless communication device mayalso provide the driver and passengers of the vehicle with telephone anddata communication service, such as the ability to place and receivephone calls through a sound-system of the vehicle, and the ability toaccess Internet content for instance.

In general, such an integrated wireless communication device will bepowered by the vehicle. For instance, when the vehicle's ignition is on,the wireless device may receive power from the vehicle's alternator ormay receive power from the vehicle's battery, which may be continuouslycharged by the alternator. When the vehicle's ignition is off, however,the battery may continue to supply power to the wireless device so thatthe device can continue to operate in a telematics mode (e.g., toreceive and respond to door-unlock commands, ignition-cutoff commands,location-reporting commands, etc.) or carry out other wireless devicefunctions.

A wireless device that is integrated with a vehicle may be arranged toenter a quiescent state when the vehicle's ignition turns off, in aneffort to conserve the vehicle's battery power. In the quiescent state,the wireless device may engage in very little processing or otherfunctionality so that the device would consume very little batterypower. To facilitate receiving telematics commands while the vehicleignition is off, however, the wireless device may periodically wake upaccording to a watchdog timer and register with the network and scan forany pertinent messages, and the device may then return to its quiescentstate.

A problem with such arrangement is that if the vehicle's ignition is offfor an extended period of time and the wireless device continues toengage in this periodic registration, the wireless device may ultimatelyexhaust the vehicle's battery power. This may happen, for instance, ifthe vehicle is parked in a garage at an airport while the vehicle owneris away on a long trip, for instance. In that scenario, when the ownerreturns from the trip the owner may find that the vehicle's battery hasdied, and the owner may be unable to start the vehicle. Further, if theowner has inadvertently locked his or her keys in the vehicle, the ownermay be unable to have a remote door-unlock command be received andprocessed by the vehicle.

One solution to this problem is to arrange the wireless device to notre-register with the network while the vehicle ignition is off. If thewireless device remains registered with the network (e.g., does notde-register) when the vehicle ignition turns off and does notre-register with the network over time while the vehicle ignition isoff, less battery power should be consumed, and the vehicle battery maysurvive an extended period of the vehicle being parked. Further,re-registration while the vehicle ignition is off may in theory beunnecessary, since the vehicle would not be driven with the ignition offand would therefore remain in the same location to the knowledge of thenetwork. Thus, inhibiting device re-registration while the vehicleignition is off is one way to help conserve the vehicle's battery power.

A problem with this solution, however, is that the vehicle may in factbe moved even though its ignition is off. For instance, the vehicle maybe towed due to illegal parking or by a thief, or the vehicle may bemoved by environmental forces such as high winds or water flow. In theseor other situations, the vehicle owner may want the vehicle to be ableto receive and respond to telematics commands, such aslocation-reporting, ignition-cutoff, or door-unlock commands forinstance. However, if the vehicle has been moved sufficiently far andthe wireless device has not re-registered with the network, the networkmay be unable to route a telematics command to the wireless device.

As a specific example, if the vehicle has been towed to a remotelocation, the owner may want to invoke a telematics command to cause thevehicle to report its location so the owner can find the vehicle.However, if the wireless device has not re-registered with the networkand the network therefore does not have data indicating the coveragearea (or paging area) in which the vehicle is located, the network mayhave difficulty sending that command to the vehicle. And as anotherexample, if the vehicle has been stolen and moved far away, the ownermay wish to invoke a telematics command to cause the vehicle to disableits ignition so that it cannot be started. However, again, if thenetwork does not know where the vehicle is located, the network may havedifficulty sending that command to the vehicle as well.

Disclosed herein is an arrangement to help overcome this problem. Asdisclosed, while the ignition of the vehicle is off, the integratedwireless communication device will operate in a reduced-registrationmode in which the device periodically determines from at least vehiclecontrol system data whether the vehicle has moved a threshold extent andthe device then responsively registers with the network only if thedetermination is that the vehicle has moved at least the thresholdextent. Further, each time the device makes this determination, thedevice may also scan the airwaves for any messages destined to thedevice.

With the benefit of this arrangement, the device can avoid engaging in,or can greatly reduce the extent to which it engages in, air interfaceregistration while being powered by the vehicle's battery.Advantageously, however, the device will also keep the network apprisedof its location when the device has moved sufficiently. The arrangementmay thereby help conserve the vehicle's battery power while retainingthe ability of the device to receive and respond to telematics commandsor to engage in other useful wireless communication functions.

These as well as other aspects, advantages, or alternatives will becomeapparent to those of ordinary skill in the art by reading the followingdetailed description, with reference where appropriate to theaccompanying drawings. Further, it should be understood that thedescription provided by this overview section and elsewhere in thisdocument is intended to illustrate the invention by way of example only.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified diagram of a system in which the exemplarywireless communication device integrated with a vehicle may beimplemented.

FIG. 2 is simplified block diagram of a wireless communication deviceintegrated with a vehicle.

FIG. 3 is a flow chart depicting functions that can be carried out by awireless device integrated with a vehicle.

DETAILED DESCRIPTION

As noted above, FIG. 1 is a simplified diagram of a system in which arepresentative arrangement can be implemented. Generally, the figuredepicts a vehicle 12 having an integrated wireless communication device14 that is arranged to communicate with a radio access network 16.

Vehicle 12 is shown by way of example as a car. In practice, however,the vehicle could take numerous other forms, including but not limitedto a van, a truck, a boat, a motorcycle, an airplane, or any othervehicle now known or later developed. Preferably, the vehicle ismotorized and includes a battery 18 that provides power to the vehicleand, at least at times, to the wireless communication device 14.However, there may be useful embodiments of the present disclosure wherethe vehicle is not motorized or where power is provided to the vehicleand/or the wireless communication device in some other manner.

Wireless communication device 14 generally provides wirelesscommunication service for the vehicle, to facilitate telematics andother communication functions such as those described above forinstance. As such, the wireless device 14 may be communicatively linkedwith, or provided as part of, a control system 20 of the vehicle,including but not limited to an industry standard on-board diagnostics(OBD) system for instance, and the wireless device may include awireless communication module that facilitates air interfacecommunication with the radio access network. Further, the wirelessdevice may include or implement logic to carry out the innovativefunctions described herein. In practice, the wireless device may bemanufactured as an integral part of the vehicle. Alternatively, thewireless device may be added on to the vehicle by a dealer or othervendor.

Radio access network (RAN) 16 comprises any network or other systemarranged to engage in air interface communication with wirelesscommunication devices such as device 14, preferably throughout a widegeographic area. By way of example, RAN 16 may comprise a cellularwireless communication network operated by a wireless carrier. As shown,such a network may include a number of base transceiver stations (BTSs)22, each providing antennas that radiate to define one or more wirelesscoverage areas, such as cell sectors or broader coverage areas (e.g.,clusters of cell sectors), in which wireless communication devices cancommunicate with the RAN according to one or more agreed air interfaceprotocols, such as CDMA (e.g., 1xRTT or 1xEV-DO), iDEN, WiMAX, LTE, GSM,HSDPA, or others now known or later developed. The RAN may then furtherinclude one or more switches, gateways, controllers, or the like 24,that provide connectivity with one or more transport networks 26.

The RAN may broadcast certain control signals respectively in eachcoverage area, for receipt by wireless devices operating in the coveragearea. For instance, in each coverage area, the RAN may broadcast a pilotsignal and/or other control signal that provides or embodies (e.g., isencoded with) an identifier of the coverage area. In CDMA systems, forinstance, the RAN may broadcast in each cell sector a pilot signal thatembodies a pseudo-noise offset (PN offset) uniquely identifying the cellsector as compared with adjacent cell sectors. Further, the RAN maybroadcast other potentially more unique identifiers of coverage areas,as well as other control information.

Further, the RAN may define in each coverage area one or more pagingchannels on which the RAN may broadcast page messages destined forparticular wireless devices. In practice, the RAN may transmit suchmessages in particular timeslots on a paging channel, and the wirelessdevice may be arranged to read the paging channel at those timeslots, insearch of any relevant page messages.

The RAN may use the paging channel or other designated air interfacechannel or channels to provide various control signals or bearer data tothe wireless device. For example, if the RAN seeks to set up a call to awireless device, the RAN may broadcast a page message for receipt by thewireless device to alert the device of the call, and the device mayreceive and respond to the page message to facilitate assignment of anair interface traffic channel over which to conduct the call. And asanother example, if the RAN has a short messaging service message, shortdata burst message, or other type of message to send to the wirelessdevice, the RAN may similarly deliver the message to the wireless devicevia a paging channel or other designated air interface channel.

Shown coupled with the RAN 16 through one or more signaling links 28 isa home location register (HLR) 30, which maintains a profile record foreach served wireless device indicating the wireless serving area (e.g.,cell, cell sector, or switch serving area) where the wireless device hasmost recently registered for service with the RAN.

In practice, as noted above, a wireless device may be set to registerwith the network periodically and/or in response to other triggerevents. To register, the wireless device may wirelessly transmit aregistration message via an air interface access channel to the RAN.Upon receipt of such a registration message from the wireless device viaa particular wireless coverage area, the RAN may then transmit aregistration notification message to the HLR 30, and the HLR may updateits profile record for the wireless device to indicate the device'scurrent serving area.

Also shown coupled with the RAN, through signaling links 32 and/or viatransport network(s) 26, is a representative messaging server 34, suchas a short messaging service center for instance, which functions totransmit messages to particular wireless devices. In practice, whenmessaging server 34 receives a message to send to a particular wirelessdevice, such as device 14 for instance, the server 34 may query HLR 30to determine the serving area where the wireless device most recentlyregistered, and the server may then transmit the message to a switch orother entity serving that area, so that the message can then be routedto the wireless device.

Shown coupled with the messaging server 34 through signaling link 36and/or via transport network(s) 26 is then a telematics server 38.Telematics server 38 may function to engage in telematics communicationvia RAN 16 with wireless devices such as device 14, so as to conveytelematics commands as described above for instance. For example, if anowner of vehicle 12 has locked his or her keys in the car, the owner maycontact telematics server 38 (e.g., a provider of server 38) to requestthat a door-unlock command be sent to the vehicle, and telematics server38 may then responsively transmit a door-unlock command to wirelessdevice 14 for processing by the vehicle control system 20. Inparticular, telematics server 38 may output the message addressed to thewireless device, and the message may be routed to messaging server 34and routed in turn via RAN 16 to the wireless device.

FIG. 2 is next a functional block diagram of wireless device 14integrated with vehicle 12 in accordance with a representativearrangement. The block diagram depicts on the right side components thatmay be considered part of the vehicle 12 and on the left side componentsthat may be considered part of the wireless device 14. It will beunderstood, however, that variations from the arrangement shown arepossible. For instance, one or more of the components shown as part ofthe vehicle may be part of the wireless device, and one or more of thecomponents shown as part of the wireless device may be part of thevehicle. Further, one or more components may be components of both thewireless device and the vehicle. Numerous other arrangement are possibleas well. Therefore, the specific arrangement shown should not be takenas limiting.

As illustrated in FIG. 2, in the representative arrangement, the vehicle12 includes an ignition 40, battery 18, control system 20, and a userinterface 46, and the wireless device 14 includes a wirelesscommunication interface 48, a data interface 50, a processor 52, anddata storage 54. Ignition 40, control system 44, user interface 46, anddata interface 50 are shown coupled with a system bus, network, or otherconnection mechanism 56. Further, wireless communication interface 48,data interface 50, processor 52, and data storage 54 are shown coupledwith another system bus, network, or connection mechanism 58. Andbattery 18 is shown coupled with at least wireless communicationinterface 48 and processor 52.

Ignition 40 functions generally to turn on or off an engine of thevehicle. The ignition may take any form now known or later developed,such as an electronic ignition for instance. In operation, when theignition is on, the engine (e.g., internal combustion engine and/orelectric motor) may be supplying power to drive the vehicle, while analternator or other mechanism may be supplying power to charge battery18, and the alternator, battery, or some other power source may besupplying power to components such as the wireless device 14. On theother hand, as noted above, when the ignition is off, battery 18 maycontinue to supply power to components such as wireless device 14, toallow continued for telematics control and other functionality.

Battery 18 may comprise any battery of a type now known or laterdeveloped. By way of example, battery 18 may be a lead-acid automotivebattery. Alternatively, the battery may be designed more specificallyfor powering components such as wireless device 14.

Control system 20 preferably stores and reports vehicle statusinformation regarding vehicle systems, such as ignition status, odometerstatus (distance traveled reading), wheel rotation data (e.g., extent ofwheel rotation), etc. The control system, which as noted above mayinclude an industry standard OBD system, may communicate over bus 56,receiving queries for the status of particular vehicle systems andresponding with the requested information. The control system mayfurther publish certain status information, so that entities incommunication with bus 56 can determine the current status of varioussystems. For instance, the control system may publish ignition stateinformation, indicating in binary (e.g., Boolean) format whether thevehicle ignition is currently on or off. Such information may beusefully employed by wireless device 14 in accordance with the presentdisclosure, to trigger operation in a reduced-registration mode when thevehicle ignition is off.

User interface 46 may comprise input and output components to facilitateinteraction with a user, such as a driver or passenger of the vehiclefor instance. As such, user interface 46 may be integrated in a dash andother user-accessible portions of the vehicle. By way of example, userinterface 46 may include a touch-sensitive display screen for presentinginformation to a user and receiving input from a user. As anotherexample, user interface 46 may be integrated with a vehicle soundsystem, including a microphone and speakers, or may provide its ownaudio interface, to allow audio interaction with a user. Other examplesare possible as well.

Wireless communication interface 48 may comprise a mobile station modemor other transceiver arranged to engage in air interface communicationwith RAN 16 according to one or more agreed air interface protocols,such as any of those noted above for instance. To facilitate this, theinterface 48 may further include or be interconnected with one or moreantennas (perhaps on the exterior of the vehicle) and may include logicto carry out functions such as engaging in air interface registrationwith the RAN and so forth. In practice, the wireless communicationinterface 48, or more generally the wireless communication device 14,may subscribe to service with a wireless carrier that operates RAN 16,with subscription and service fees being paid by the vehicle owner or byanother party.

Data interface 50 may comprise a proprietary or standard connectionmechanism (e.g., pin-out port) through which the wireless deviceconnects with the vehicle, so as to communicate with the vehicle controlsystem, to receive vehicle status information and to provide telematicscommands such as those discussed above for instance.

Processor 52 may comprise one or more general purposes processors (e.g.,INTEL processors) and/or one or more special purposes processors (e.g.,digital signal processors or application specific integrated circuits).Further, the processor 52 may be integrated in whole or in part with thewireless communication interface 48. For instance, the wirelesscommunication interface may be arranged to control periodic registrationand may further be arranged to manage operation in thereduced-registration mode in accordance with the present disclosure.

Data storage 54, in turn, may comprise one or more volatile and/ornon-volatile storage components, such as magnetic, optical, orsolid-state (e.g., EEPROM or flash) memory for instance and may beintegrated in whole or in part with processor 52. As shown, data storage54 may hold program instructions executable by processor 52 to carry outvarious functions described herein, such as to cause wireless device 14to operate in a quiescent mode, to wake up periodically in accordancewith a watchdog timer and to then determine, based on at least vehiclecontrol data, whether the vehicle has moved more than a threshold extentsince the processor last checked, and, if so, to trigger air interfaceregistration.

FIG. 3 is next a flow chart depicting functions that can be carried outby a wireless device integrated with a vehicle as presentlycontemplated. Wireless device 14 may carry out the functions of FIG. 3in response to the ignition 40 of vehicle 12 being turned off and whilethe ignition is off, which wireless device 14 may determine fromignition-state data provided by control system 20. The wireless device14 may likewise carry out the functions of FIG. 3 at other times aswell. However, carrying out the indicated functions is believed to beparticularly advantageous when the vehicle ignition is off, in an effortto help conserve power of battery 18.

As shown in FIG. 3, at block 60, the wireless device operates in aquiescent state in which the device does not automatically engage inperiodic air interface registration with the RAN, and the wirelessdevice applies a watchdog timer to facilitate periodic performance ofthe subsequent steps. The watchdog timer is preferably set to triggerthe subsequent steps at an interval that is sufficiently long to helpconserve battery power. (As such, the wireless device or other entitycould be arranged to automatically extend the interval of the watchdogtimer in response to detecting that the remaining power of battery 18has dropped to below a defined threshold level, so as to further helpconserve battery power.) Each time the watchdog timer fires, aninterrupt or other process causes the wireless device to then proceed toblock 62.

At block 62, the wireless device momentarily wakes from its quiescentstate and receives vehicle-movement data from the vehicle. The wirelessdevice may receive the vehicle movement data from control system 20 viabus 56 or in some other manner from the control system 20.

In an example embodiment, the vehicle-movement data may be odometer dataand/or wheel-rotation data, both of which may provide a fairly accurateindication of whether the vehicle has been moved since a last readingfor instance. This data may be established in a known manner by one ormore sensors in the vehicle, such as magnetic sensors for reading fullor partial wheel rotations, and the sensor readings may be stored by thecontrol system 20, such as an OBD system. In practice, many vehiclestoday are arranged to record odometer changes even when the vehicleignition is off. Further, vehicles may also record wheel-rotation datawhen the vehicle ignition is off, or may do so upon power being suppliedto a wheel-rotation sensor. Power could be supplied to thewheel-rotation sensor in the same manner that power can be supplied tolights and/or a siren by a master alarm system, in response todoor-handle-movement or accelerometer sensor detection, or in some othermanner.

Through a query to the control system 20, the wireless device may thusdetermine an extent to which the vehicle has moved, at least in terms ofwheel movement, from a last reading. Other vehicle control data forindicating vehicle movement, including wheel movement and/or lateral orother movement, from sensors now known or later developed, may be usedin addition or instead. Optimally, this determination of the extent towhich the vehicle has moved may be made without consideration of globalpositioning system data, to avoid the need to receive and process suchdata.

At block 64, the wireless device makes a determination, based at leaston the received vehicle-movement data, of whether the vehicle has movedat least a threshold extent. The threshold extent for this purpose canbe defined by the wireless device manufacturer and/or by a user ortechnician through user-interface 46, or in some other manner. Further,making the determination of whether the vehicle has moved more than athreshold extent may involve reading data that indicates an extent ofmovement since a last reading by the wireless device and/or comparingdata indicating location as of a last reading with location as of a newreading, to determine distance travelled, or may take some other form.Distance, for this purpose, may be measured in traditional units such asinches, feet, miles, or kilometers, or the like, and/or may be measuredin other units, such as number of wireless coverage areas traversed.

In practice, the wireless device may be arranged to use vehicle controlsystem data (e.g., odometer and/or wheel-rotation data) alone as a basisto make the determination of whether the vehicle has moved the thresholdextent at block 64. For instance, the wireless device may query thecontrol system 20 to determine a current odometer reading and maycompute a difference between that reading and an odometer readingrecorded by the wireless device at the time the ignition turned off orat a time of latest registration. The wireless device may then determinewhether that difference is at least the threshold extent.

Alternatively, the determination of whether the vehicle has moved atleast the threshold extent could be a two (or more) part determination.For instance, the wireless device may first make a determination fromthe vehicle control system data (e.g., odometer data and/orwheel-rotation data) that the vehicle has moved at least a firstthreshold extent, which may be a relatively short distance such as mereinches or feet. In response to making that first determination, thewireless device may then make a second determination based on wirelessnetwork data of whether the vehicle has traversed a threshold number ofwireless coverage areas or simply whether the vehicle has moved into anew coverage area.

To facilitate making this second determination, the wireless device mayrecord the broadcast identity of one or more wireless coverage areas inwhich the device is located at the time the vehicle ignition turns offor at the time of the device's last registration. To make the seconddetermination, the device may then determine the broadcast identity ofone or more wireless coverage areas in which the device is currentlylocated and may compare the determined wireless coverage area identityor identities with the recorded identity or identities. The device maythereby determine whether the vehicle has traversed a threshold numberof wireless coverage areas (e.g., moved into a new coverage area, ortraversed some other number of coverage areas), as the determination ofwhether the device, and thus the vehicle, has moved at least thethreshold extent.

Further or alternatively, if the device has access to wireless coveragearea mapping data, the device may use the coverage area identifiers andthe mapping data as a basis to determine how far the device travelledsince the ignition was turned off or since the device's lastregistration with the network. The device may then determine if thatdistance is at least the threshold extent.

If the determination at block 64 is that the vehicle has not moved atleast the threshold extent, then the wireless device does not proceed toblock 66. Instead, the wireless device may return to block 60, operatingin the quiescent state and waiting for the watchdog timer to fire again.

On the other hand, if the determination at block 64 is that the vehiclehas moved at least the threshold extent, then the wireless deviceproceeds to block 66. At block 66, the wireless device then engages inair interface registration with the RAN 16. For instance, the processor52 may cause the wireless communication interface 48 to transmit aregistration message via an air interface access channel to the RAN asdescribed above. Furthermore, the wireless device may then scan an airinterface paging channel, at a next scheduled timeslot for instance, insearch of any messages that the RAN is transmitting to the wirelessdevice and, upon receipt of any such messages, may process the messages.The wireless device may then return to block 60, operating in aquiescent state and waiting for the watchdog timer to fire again.

In normal practice, when the vehicle ignition is on, the wireless devicemay periodically engage in air interface registration without regard tomovement of the vehicle. With the benefit of the present process,however, when the vehicle ignition is off, the wireless device may avoidperiodically engaging in air interface registration, or may engage inair interface registration less often than the wireless device doeswhile the vehicle ignition is on, thus helping to conserve vehiclebattery power.

Further, to avoid having the wireless device receive and processrelatively low-priority messages (e.g., non-telematics messages) whilethe vehicle ignition is off, the wireless device may arrange forlow-priority messages to be held while the ignition is off.

For instance, when the wireless device detects that the vehicle ignitionturns off, the wireless device may re-register with the RAN (e.g., mayde-register and then re-register, or may simply re-register with theRAN), and as part of the re-registration process may signal to the RANto cause low-priority messages to be held. By way of example, thewireless device may include in its registration message a specialparameter that the RAN will interpret to mean that low-priority messagesdestined to the wireless device should be held. The RAN may then signalto the messaging server 34 to cause the messaging server to hold suchmessages. Alternatively, the wireless device may send a control signaldirectly to the RAN or messaging server to request holding of suchmessages. Until further notice, the messaging server may then holdlow-priority messages for the mobile station, but may still route to themobile station any other messages, such as particular telematicsmessages for instance.

When the wireless device then detects that the vehicle ignition turnsback on, the wireless device may then re-register with the RAN again andprovide a signal to request any previously-held messages to be sent tothe wireless device.

An exemplary embodiment has been described above. It should beunderstood, however, that variations from the embodiment discussed arepossible, while remaining within the true spirit and scope of theinvention as claimed.

We claim:
 1. A wireless communication device integrated with a vehicle,the wireless communication device being arranged to operate in a firststate while an ignition of the vehicle is off, wherein, in the firststate while the ignition of the vehicle is off, the wirelesscommunication device carries out functions comprising: (i) receivingvehicle-movement data from the vehicle, (ii) making a determination,based at least on the received vehicle-movement data, of whether thevehicle has moved at least a threshold extent, and (iii) only if thedetermination is that the vehicle has moved at least the thresholdextent, then responsively engaging in air interface registration with aserving radio access network.
 2. The wireless communication device ofclaim 1, wherein the vehicle-movement data comprises at least one ofwheel-rotation data and odometer data.
 3. The wireless communicationdevice of claim 2, wherein, in at least the first state, the wirelesscommunication device is powered by a battery of the vehicle.
 4. Thewireless communication device of claim 2, wherein, in the first state,the wireless communication device carries out the functions periodicallyin accordance with a watchdog timer.
 5. The wireless communicationdevice of claim 2, wherein the wireless communication device is furtherarranged to operate in a second state when the ignition of the vehicleis on, wherein, in the second state, the wireless communication deviceperiodically engages in air interface registration without regard tomovement of the vehicle.
 6. The wireless communication device of claim5, wherein in the first state, the wireless communication device doesnot periodically engage in air interface registration.
 7. The wirelesscommunication device of claim 5, wherein in the first state, thewireless communication device engages in air interface registration lessoften than the wireless communication device engages in air interfaceregistration in the second state.
 8. The wireless communication deviceof claim 5, wherein the wireless communication device transitions fromthe second state to the first state when the ignition of the vehicletransitions from an on state to an off state.
 9. The wirelesscommunication device of claim 2, comprising a wireless communicationinterface for engaging in air interface communication, wherein theregistration occurs via the wireless communication interface.
 10. Thewireless communication device of claim 2, wherein the functions alsoinclude scanning for any incoming messages to the wireless communicationdevice.
 11. The wireless communication device of claim 2, wherein thewireless communication device is arranged to transition from the secondstate to the first state in response to the ignition of the vehiclebeing turned off, and wherein the wireless communication device isarranged to engage in air interface registration in connection with thetransition and, as part of the air interface registration in connectionthe transition, to request that low-priority messages for the wirelesscommunication device be held.
 12. The wireless communication device ofclaim 2, wherein the wireless communication device is communicativelylinked with an on-board diagnostics system of the vehicle and receivesthe data from the on-board diagnostics system.
 13. The wirelesscommunication device of claim 2, wherein the wireless communicationdevice makes the determination of whether the vehicle has moved at leastthe threshold extent without the wireless communication devicereferencing global satellite positioning data.
 14. The wirelesscommunication device of claim 1, comprising a wireless communicationinterface for engaging in air interface communication, wherein theregistration occurs via the wireless communication interface, andwherein making the determination of whether the vehicle has moved atleast the threshold extent further comprises: making a firstdetermination, based on the data, of whether there has been thresholdmovement of the vehicle; and responsive to the first determination beingthat there has been threshold movement of the vehicle, evaluatingbroadcast data received by the wireless communication interface to makea second determination of whether the wireless communication device hastraversed at least a threshold number of wireless coverage areas and, ifso, concluding that the vehicle has moved at least the threshold extent.15. The wireless communication device of claim 1, wherein engaging inair interface registration with the serving radio access networkcomprises transmitting via an air interface access channel to theserving radio access network a registration message that serves toregister the wireless communication device as operating in a particularcoverage area of the radio access network.
 16. A wireless communicationdevice integrated with a vehicle, the vehicle having an ignition and acontrol system, the wireless communication device comprising: atransceiver for engaging in air interface communication with a servingradio network; a data interface for communicating with the controlsystem; and a processing unit arranged to cause the wirelesscommunication device to operate in a reduced-registration mode while thevehicle ignition is off, wherein, in the reduced-registration mode, theprocessing unit carries out functions comprising (i) receivingvehicle-movement data from the control system via the data interface,(ii) using the received data as a basis to make a determination ofwhether the vehicle has moved at least a threshold extent, (iii) causingthe transceiver to engage in air interface registration with the radionetwork in response to the determination, if the determination is thatthe vehicle has moved at least the threshold extent, and (iv) notcausing the transceiver to engage in air interface registration with theradio network in response to the determination, if the determination isthat the vehicle has not moved at least the threshold extent.
 17. Thewireless communication device of claim 16, wherein the vehicle-movementdata comprises at least one of wheel-rotation data and odometer data.18. The wireless communication device of claim 16, wherein the functionsfurther comprise causing the transceiver to scan for any messagesdestined to the wireless communication device.
 19. The wirelesscommunication device of claim 16, wherein the processing unittransitions the wireless communication device to thereduced-registration mode in response to detecting transition of thevehicle from an ignition-on state to an ignition-off state.
 20. Thewireless communication device of claim 19, wherein upon transitioning tothe reduced-registration mode, the wireless communication devicetransmits a message to the radio network to request holding oflow-priority messages destined to the wireless communication device.